Tubular boiler.



No. 727,480- PATENT-ED MAY 5, 1903.-

J. S. STEVENS.

TUBULAR BOILER.

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No. 727,480- PATENTED MAY 5, 1903., J. s. STEVENS. I

TUBULAR BOILER.

APPLICATION FILED 0OT.13, 1902.

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Patented May 5, 1903.

PATENT OFFICE.

JAMES S. STEVENS, OF PUEBLO, COLORADO.

TUBULAR BOILER.

- SPECIFICATION forming part of Letters Patent No. 727,480, dated May 5,1903.

Application filed October 13,1902. Serial No. 127,160. (No model.)

To all whom it may concern:

Be it known that LJAMES S. STEVENs,a citizen of the United States,residing at Pueblo, county of Pueblo, and State of Colorado, haveinvented a new and useful Tubular Boiler, of which the following is aspecification.

The invention relates to certain improve ments in water-tube boilers;and it has for its principal object to provide a construction of tubularboiler in which the products of combustion will be directed into contactwith all portions of the tubes and in which the circulation of the waterwill be continuous and follow a number of cycles in order that it may bethoroughly exposed to the action of the heat and quickly vaporizedwithout waste of fuel.

A further object of the invention is to improve the construction andarrangement of the baffie-plates between the banks of tubes in orderthat the flame and products of combustion may be directed into intimatecontact with the entire length of said tube.

With these and other objects in View the invention consists in the novelconstruction and arrangement of parts hereinafter described, illustratedin the accompanying drawings, and particularly pointed out in theappended claims, it being understood that various changes in the form,proportions, size, and minor details of the structure may be madewithout departing from the spirit or sacrificing any of the advantagesof the invention.

In the accompanying drawings, Figure 1 is a sectional elevation of awater-tube steamboiler constructed in accordance with the invention.Fig. 2 is a perspective diagram illustrating the water circulation. Fig.3 is a sectional elevation of a steam-drum, illustrating the applicationthereto of a strainer for preventing the entrance of liquid-to thesteampipe.

Similar numerals of reference are employed to indicate correspondingparts throughout the several figures of the drawings.

In the drawings, 1 designates the front wall of a furnace, and 2 therear wall thereof, and within said furnace is a combustion-chamber 4:and a grate 5. In the upper portion of the furnace are two parallelsteam-drums 6 and 7, and in the lower portion, at a point to the rear ofthe grate-wall, is a mud-drum 8 of much larger area than either of theupper drums 6 and 7. The upper drum 6 and lower drum 8 are connected bya rear bankof tubes arranged in rows, there being four of such rows inthe present instance, as indicated at 10, 11, 12, and 13 of Fig. 1. Theupper drum 6 is connected by the feed-pipe 13 to asource ofwater-supply, through which water is fed to the boiler and thencedescends from the upper drum 0 through the rear bank of tubes to themud-drum 8. The mud-drum and the upper drum 7 are connected by a centralbank comprising a plurality of rows of tubes 14, 15, 16, and 17, thetubes of the rear rows 14 and 15 being arranged closely together foralmost their entire length to form a watertube bafile-plate. At a pointnear the lower ends of the tubes the tubes of the rear row are bent at agreater angle than those of the row 15, only a slight space being leftfor the passage of the products of combustion and this space beingpartly filled with asbestos or similar material, as indicated at 18, inorder to force the products of combustion to travel the full length ofthe central bank of tubes. The bending of the rear tubes 14 in themanner described is quite advantageous in that the tube is presented tothe mud-drum in aradial line from the center of the drum and may beconnected without straining and without danger of leakage. In the upperdrum 7 is a division-plate 19, extending between the two rows of tubes15 and 16 in order to divide the current of water. The upper and lowerdrums 7 and 8 are further connected by the front bank, comprising tubes20, 21, 22, and 23, the tubes of the rear rows 20 and 21 being closelyarranged in order to form a baffle-plate and slightly separated fromeach other at their upper ends to form a passage for the products ofcombustion and in order that they may be properly connected to the upperdrum. The spaces between the upper ends of the tubes 14 and 15 may befilled with asbestos or similar material in order to prevent the passageof the products of combustion.

The water-space of the upper drums may extend to a point coincident withthe horizontal axes of the drums; but the water-line is always above allof the tubes. A connecting-pipe 24 leads from one drum to the other IOOat a point below the water-line, while there may be any desired numberof such tubes to facilitate circulation of the water.

At a point to the rear of the baffle-plate formed by the tubes 20 and 21and immediately below the point where such tubes separate is awater-drum 25, connected at one end to'the drum 6 by a pipe 26 and atthe opposite end being connected to the drum 7 by a pipe 27, saidwater-drum serving as an auxiliary to the baffle-plate and deflectingthe products of combustion against the watertubes of the central bank.

The tops of the drums are connected to an enlarged pipe 28, serving as asteam-dome and from which leads the main steam-pipe 29 to the engine orother point where the steam is to be utilized. The steam-dome and theforward drum 7 are connected in the usual manner to a gage 30, and thecentral portion of the dome 28 is connected by a drain-pipe 31 to one ofthe upper drums.

The products of combustion from the firebox travel up in contact withthe front bank of tubes until the spaced portions of the baffleplateformed by the tubes 20 and 21 is reached and thence are deflected by thedrum 26 against the central bank of tubes, following downwardly untilthey pass through the spaces between the tubes 14 and 15 and thenceupwardly in contact with the rear bank of tubes to the escape-flue.

The feed-water enters the drum 6 and passes down through the rear bankof tubes to the mud-drum, a portion of the water traveling up throughthe tubes 14 and 15 of the central bank to the front drum 7 and thencethrough tube 24 to the rear drum 6. A further circulation is maintainedfrom the mud-drum up through the central bank of tubes and return to themud-drum through the tubes 16 and 17 of the central bank, a portion ofthewater also passingdown through the pipe 26 to the water-drum 25 andthence upwardly through the pipe 27 to the rear drum 6. The plate 19divides the water between the tubes 15 and 16, or it might be placedbetween the tubes 14 and 15 to afford an increased outlet for the waterentering the front drum through the forward bank of tubes.

The water is circulated continuously, and the connections between thetubes and the drums are such as to afford a number of courses for thewater, so that it is rapidly heated and soon passes off in the form ofvapor.

In order to prevent the passage of water to the steam-dome and to theengine or other point at which the steam is utilized, I employ astrainer at the points of connection of the steam-drum with the upperdrums 6 and 7. Each strainer is in the form of a perforated cone formedof sheet metal and has at its base portion a peripheral flange 34,fitting between the bolting-fianges of the drums. These strainers serveto prevent the passage of liquid, and the steam is thoroughly dried.

As an additional precaution a strainer 33 is also placed at the point ofconnection between the steam-dome and the main steampipe leading fromthe boiler, and immediately below this conc, the lower wall or bottom ofthe dome is depressed to form a drip-chamber, with which communicatesthe drain-pipe 31 to convey the water back to the boiler proper.

In some cases, especially where one of the upper drums is dispensed within order to decrease the capacity of the boiler, the steamdome may beconnected to a single drum in the manner indicated in Fig. 3, theoperation remaining the same, although in this instance the oppositeends of the pipe which forms the steam-dome are both connected to thesame drum. In both structures the auxiliary drainpipe is preferablyextended to a point below the water-line in order to prevent the passageof steam from the drum directly to the steam-dome.

Having thus described my invention, what I claim is 1. The combinationin a steam-boiler, of a pair of upper drums communicating with eachother, a lower mud-drum, a plurality of banks of tubes extending fromthe mud-drum to the front of the upper drums, a rear bank of tubesextending from the mud-drum to the upper rear drum, and a divisionplatedisposed in the upper front drum at a point between the tubes which formthe central or intermediate bank, dividing the drum into twocompartments.

2. The combination in a steam-boiler, of the upper front and rear drums,a water-feed pipe communicating with the rear drum, water-tubesextending directly between the two drums, a lower mud drum, a pluralityof banks of tubes of which the rear bank conmeets the upper rear drum tothe mud-drum and the forward bank connects the mud-drum to the upperfront drum, a central bank of tubes connecting the mud-drum to the upperfront drum, and a division-plate in said upper front drum disposed at apoint between the ends of the tubes of the central bank.

3. The combination in a steam-boiler, of front and rear upper drums, alower muddrum, front and intermediate banks of tubes extending from themud-drum upwardly to the front drum, a rear bank extending from themud-drum upwardly to the rear drum, and an inclined division platearranged in the front drum at a point midway of the tubes which form theintermediate bank.

In testimony that I claim the foregoing as my own I have hereto afiixedmy signature in the presence of two witnesses.

JAMES S. STEVENS.

Witnesses:

JEPTHA MILTON WITT, WILLIAM D. KoEN.

